A radar sensor for adaptive distance and cruise control is described in the publication “adaptive Fahrgeschwindigkeitsregelung ACC” [Adaptive cruise control ACC] published by Robert Bosch GmbH, April 2002 (ISBN-3-7782-2034-9). The radar sensor emits radar beams and receives partial beams reflected back by objects within the sensor coverage area and carries out a cruise control in the sense of controlling a constant distance as a function of the measured relative velocity and the distance of objects ahead and, in the absence of objects ahead, carries out a cruise control in the sense of controlling a constant velocity.
A disadvantage of radar sensors for distance and cruise control is that the reflection points of the detected objects which reflect back the emitted radar beam are variable, depending on the angle of observation, and thus the reflection points of the objects ahead may migrate constantly on the object. This results in a measurement inaccuracy which is superimposed on the measured variables of distance d, azimuth angle φ of the object with respect to the main axis of the sensor, and relative speed vrel as measuring errors which are manifested in a statistical noise of these measured variables.